The immense amount of raw sewage in the lake was attributed to low water flows, and the lack of southern locks to allow water to more freely pass out of the lake. Nonetheless, a year later city officials were advocating that a playground be built on the shores of Kingman Island. A number of development proposals were made for Kingman Lake throughout the 1960s. The National Capital Parks Commission banned boating on the lake in October 1961. The Commission also proposed filling in of Kingman Lake (about 50 to 60 percent of the lake's total area) and relocating some of the riprap walls, making Islands 3 and 4 part of the mainland and adding to Langston Golf Course (located on the northern half of Kingman Island). This plan was never acted on. Recent development Since 1999, a variety of proposals have been made for Kingman Lake, most focusing on retaining the lake's character as one of the few remaining wild places within the city's limits. In September 1999, the Army Corps of Engineers—which retained ownership of Kingman Lake—began transforming the lake back into a tidal marsh. The Corps said it would remove some of the riprap wall and create of marsh north of Benning Bridge and of marsh between Benning Bridge and East Capitol Street Bridge. Work on the tidal marsh would be complete by March 2000, and during the summer of 2000 the Corps intended to plant tens of thousands of aquatic plants in the new marshlands. The cost of the wall removal, marsh restoration, and plantings was estimated at $4 million. A five-year scientific effort would monitor changes in the tidal marsh from 2001 to 2006. Deaths and accidents Deaths and accidents in and around Kingman Lake have unfortunately been numerous. The first confirmed death in Kingman Lake occurred on August 5, 1937, when William O'Bryant, a 19-year-old African American youth, drowned in the lake in front of two friends after diving from a fishing boat. Over the next four decades, at least 31 people drowned in the lake. Some of the more unusual accidents and deaths involving the lake include: In October, 1941, police found the bones of Omara Wilson, 50, a squatter living on Kingman Island, who had been eaten by a wild dog. On January 22, 1943, a two-engine U.S. Army Air Corps transport plane piloted by Brigadier General Luther S. Smith crashed in Kingman